Extendible drawer slide



g 31, 1965 E. c. BULLocK ETAL 3,203,749

EXTENDIBLE DRAWER SLIDE 2 SheetsSheec l Filed July 3l, 1963 Aug- 31,1965 E. c. BULLocK ETAL 3,203,749

EXTENDIBLE DRAWER SLIDE Filed July l, 196s 2 sheets-sheet 2 INVENTORS`4,645 6'. 50M 06X Wi/AA! E Olii! United States Patent O 3,203,749EXTENDIBLE DRAWER SLIDE Earle C. Bullock, Grand Rapids, and Adrian R.Olree, Caledonia, Mich., assignors to Steelcase, Inc., Grand Rapids,Mich., a corporation of Michigan Filed July '31, 19'63, Ser. No. 298,8954 Claims. (Cl. 'S12- 339) This invention relates to extensible drawersupports, and more particularly `to extensible drawer support railassemblies including a case rail, suspension rail, and a drawer rail,and normally employed to support drawers in cabinets such as tilecabinets.

The extension of drawer support rails separated by antifriction meanssuch as balls, is conventionally purposely limited by placingcooperative stops on the rails to abut the opposite sides of the balls.The stops extend into the ball raceways. When the rail-s are extended tothe maximum the balls are each trapped between two of the stop bosses.

When a heavily loaded drawer is extended to the limit, a considerableimpact force is momentarily concentrated on the stops to halt Ithemoving drawer. The stops must therefore be extremely sturdy andresistant to shear to withstand this sharp impact force. Failure of thestops, 'allowing over-extension of the drawer support could readilyresult in a serious accident. As a consequence, the stops areconventionally formed of rigid metal elements, often integrally formedfrom the rails themselves.

When these metal stops abut the intermediate steel ball as the drawerreaches maximum extension, the audible clunk is very noticeable, andoften disturbing throughout the oilice in which the flle cabi-net islocated. This factor has heretofore been considered an unpleasant butnecessary distraction. This concentrated impact force not only resultsin undesirable noise, but also, and probably more important, it causesjarring and vibration of the entire cabinet framework tending to weakenit.

It is therefore an object of this invention to provide a drawersuspension support having the stundiness and reliability of aconventional support employing rigid metallic stops, while at the sametime achieving `an extremely quiet and cushioned stop operation. Thetraditional clunk occurring with extension to the limit, and theaccompanying jarring of the framework is actually eliminated.

It is another object of this invention to provide a resilient drawerrail stop assembly that employs a resilient rubber or rubber-likeelement for cushioned stop abutment, but which is not sheared off by theconcentrated impact force due to its unique mounting. Rather, thegreater the impact force the more the rubber stop element is forcedagainst the wall of the rail for stability.

It is another object of this invention to prov-ide a resilient drawerrail stop employing a metallic mounting clip for securement of aresilient bumper to the wall of the rail, yet not requiring any spotwelding or bolting for atrtachment of lthe clip to the r-ail.

It is another object of this invention to provide a rail supportassembly employing a cushioned resilient stop assembly, but which, ineven case of failure of the resilient stops, will not allowover-extension of the drawer to cause an accident.

Still another object of this invention is to provide a drawer supportresilient stop assembly that not only has cushioned stop advantages, butalso is simple in yconstruction, relatively inexpensive to manufact-ureand assemble, and rapid and easy to assemble.

These and several Aother objects will become apparent upon studying thefollowing specilication in conjunction with the drawings in which:

FIG. 1 is a side elevational view of the novel drawer support assemblywith the rails extended;

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FIG. 2 is a side elevational View of the drawer support assembly withthe rails in close-d position;

FIG. 3 is a sectional elevational view taken on plane III-IH of thesupport assembly in FIG. 2;

tFlG. 4 is a perspective enlarged view of the resilient bumper elementof the novel stop assembly;

FIG. 5 is a perspective enlarged View of the metallic mount-ing clip forythe resilient bumper illustrated in FIG. 4, to form a bumper stop;

FIG. 6 is .an enlarged, fragmentary sectional view of a portion of therail wall and stop assembly taken on plane Ill-III of FIG. 2;

FIG. 7 is a fragmentary enlarged plan View of cooperative stop elementsin the abutment on opposite sides of a ball;

FIG. 8 is an end elevational View of the ra-il assembly illustrated inFIG. 2, .taken on plane VEL-VIII;

FIG. 9 is a sectional view of the rail assembly illus- 'tr-ated in FIG.2 taken on plane IPC-1X.

Referring now specifically to the drawings, the drawer suspensionsupport assembly 10 includes a .drawer rail 12, a suspension rail 14,and a case rail 16.

A pair of these suspension assemblies is used to support a drawer yonthe drawer rail, in a cabinet case. The forward end of the case rail 16is secured to the case frame by intertting rivets with key hole shapedslots or the like. On back end of each case rail, is an L-shaped plate20 having a rear flange and bottom flange. It attaches the rear of thecase rail to the wall of the case. On the back flange of this bracket orplate is a pair of resilient pads 22 and 24 for cushioned abutment ofthe drawer and suspension rail respectively when the drawer is cl-osed.

Preferably, all three rails are formed of a plurality of identicalchannel sections. More specifically, referring to FIG. 8, drawer rail 12is formed of one channel, case mail 14 is formed of an upper channel 14positioned inversely to and secured to a lower like channel 14 byweldment, and case rail 16 is formed of one channel inverted withrespect to drawer rail 12.

Each of the channels is generally C-shaped, having a pair of parallelarms 26 and 28 (see channel 16, FIG. 3) connected by a web Si). At theend of the arms 26 and 28, remote from web 30, is a pair of ilanges 32and 34. Flange 32 extends outwardly of the channel, while flange 34extends inwardly of the channel, with outwardly extending ange 32 beingslightly offset from inturned llange 34 whereby it is cl-oser to web 26.

The lower portion of drawer rail 12 is telescopically inter-fitted withthe upper channel of the suspension rail 14. Further, the upper portionof case rail 16 is ftelescopically interfitted with the 'lower channelof suspension rail 14.

This telescopic intertt-ing denes six ball raceways between the rails,three raceways 40, 42, 44 (FIG. 9) being between the upper drawer .railand the upper half `of the suspension rail, and three additionalrace-,ways 46, 48, and S0 being between the lower 'half of thesuspension rail and the ease rail. .In the four outermost raceways 40,42, 48, and Si), two balls are used in each to separate the rails andallow frictionless movement there between. Thus, referring .to FIG. 2,raceway 40 includes balls 54 and 56, raceway 42 includes balls 58 an-d60, raceway -48 includes balls 62 and 64, and raceway 50 includes -balls66 and 68.

The two centrally located raceways 44 and 46 each include only one ball;ball 74 at the forward end of upper central raceway 44, and ball 76 atthe rear end of the lower central raceway 46. Supplying the additionalrolling contacting and spacing means in the central raceways is adisk-shaped propulsion roller 80. This propulsion roller 80 ispositioned in a narrow elongated vertical opening extending through theconnecting arms of the two channels forming the suspension rail. It isrotatably and irremovably mounted in this position to the suspensionrail by an elongated horizontal axle 82 positioned in an elongatedhorizontal opening drilled crosswise through the connecting arms of thetwo channels. The propulsion roller cannot become dislodged out of itsposition or become misaligned even when the drawer rail is extended tothe position illustrated in FIG. 1 where the drawer rail is out ofcontact with the roller and then is pushed back into contact over theroller upon closing the drawing. The upper portion of the rollernormally contacts and bears against the lower leg of the drawer rail,while the lower portion of the roller contacts and bears against theupper leg of the case rail.

Movement of the rails with respect to each other during rail extensionoccurring with opening of the drawer, is limited by a plurality ofunique cooperative cushion stops 90, 92, 94, and 96. Stop assembly 90 ismounted to the drawer rail, stop assembly 92 to the upper channel of thesuspension rail, stop assembly 94 to the case rail, and stop assembly 96to the lower channel of the suspension rail.

Stop assemblies 90 and 92 cooperate with each other ast-raddle rollerball 60 in a manner to be described hereinafter. Likewise stopassemblies 94 and 96 cooperate with each other astraddle roller ball 64,when the drawer rail is extended as in FIG. 1. Stop assembly 90 islocated approximately in the central section of the drawer rail, stopassembly 92 being located at the front end of the case rail upperportion, stop assembly 95 being located in the centeral portion of thelower channel of the suspension rail, and stop assembly 94 being locatedat the forward end of the case rail.

Each of the stop assemblies includes two main components, a resilientbumper 100 and a metallic clip 102 (FIGS. 4, 5, and 6). The resilientbumper element 100 is preferably of rubber or rubber-like material,i.e., an elastomer of useful, self-supporting characteristics. It has agenerally wedge-shaped nose which tapers diagonally toward the wall ofthe rail on which it is mounted (see for example the drawer rail wall104 shown in FIG. 6). The tapered face 106 is at an angle of about 45degrees, more or less, with respect to the face of wall 104. Theresilient bumper has a transverse slot 108 (FIG. 4) and an elevated rearportion 110I to interiit with a generally C-shaped portion of clip 102,with leg 112 of the C-shaped portion being foreshortened. The rearwardlyprotruding tail or leg 114 of the clip extends into a slot formed bysevering parallel slits into the rail wall, and deforming a tab 116inwardly of the rail wall 104. Insertion of the tail 114 yof clip 102within the slot under this tab causes the C-shaped portion of the clipfacing the wall to retain the rubber bumper against the wall. The rubberbumper may also be adhered to the wall with a suitable adhesive.

A force in the direction of the arrow illustrated in FIG. 6 by a ball onthe tapered face 106 of the rubber bumper causes the rear face 118 ofthe slot in the bumper and the back end 120 of the rubber bumper, tobear against the transverse sufaces of the clip, preventing movement ofthe stop assembly. Movement is also limited by contact of the C-shapedportion with tab 116. Each of these stops or stop assemblies thereforeis within one of the raceways. Preferably these particular raceways 42and 48 are slightly larger (FIG. 8) and accommodate slightly largerroller balls.

When the drawer is opened to extend the drawer rail assembly, stopassembly 90 moves toward stop assembly 92, and stop assembly 96 movestoward stop assembly 94. Referring to FIG. 7, the two cooperative stopassemblies 90 and 92 move to a position straddling the intermediateroller ball 60 (see FIG. l) so that the ball is pressed between the twodiagonal surfaces of the rubber bumper elements. This creates a forceperpendicular to the tapered faces of the bumper elements, such that theforce applied creates a pressure forcing the rubber bumper elementstightly against the walls of the respective rails. Consequently, insteadof a potential shearing action occurring on the stops, a greater forcemerely increases the resistance 0f the elements, to thereby effect aunique and dependable stop assembly. The resilient bumpers substantiallyeliminate all noise normally occurring, and also the jarring vibrationswhen the suspension rail is suddenly pulled to the limit. Whileextension of the drawer rail with respect to the case rail is limited bythis cooperation between assemblies and 92 over ball 60, extension ofthe suspension rail with respect to the case rail is limited by stopassemblies 94 and 96 astraddle ball 64.

As a safety factor, in case of possible failure of the resilient stopelements, supplemental metallic stop assemblies are employed in a mannersuch that these do not normally engage, but may in case of slightoverextension of the drawer rails. Thus, referring to FIG. l, a boss isslit on one edge and deformed from the rear portion of the suspensionrail, and a corresponding reversed boss 132 is deformed from the centerportion of the case rail. Likewise (referring to FIG. 1) a boss 134 isdeformed from the rear of the drawer rail, while a cooperative boss 136is deformed from the central portion of the upper channel of thesuspension rail. The position of these bosses during the closed drawerposition of the rails is illustrated in FIG. 2. Each of these stops isbasically of a semi-conical configuration (see FIG. 9). Bosses 130 and132 are on opposite sides of ball 62, while bosses 134 and 136 straddleball 58. Each of the bosses protrude inwardly into the raceway, as shownin FIG. 9, so that with the ball positioned between the bosses, they canabut the ball and prevent further movement. Normally these bosses do notmove close enough to abut the intermediate ball (see FIG. 1), and onlydo so in case of failure of the previously resilient stops abutting toprevent significant accidental over-extension of the support assembly.In FIG. 9 the bosses 136 and 132 are shown in phantom, as well as theballs cooperative therewith, to illustrate the cooperative actiontherebetween.

This invention provides for the iirst time, as far as is known, aquietly operating, dependable, stable, safe, cushioned actioneliminating jarring of the frame and providing dignity to the operationof the case drawers. 'I'he assembly actually achieves, simultaneously,the usually incompatible features of (l) resilient cushioned stop meansand (2) safety and structural stability. Various additional advantageswill undoubtedly occur to those skilled in this art upon studying theforegoing form of the invention, and the principles applicable thereto.It is conceivable that certain minor modications could be made in theparticular structural arrangement depicted as the exemplary form of theinventive concept, without departing from the principles taught.Consequently, the invention should be accorded reasonable protection notlimited to the particular structural form presented, but only by thescope of the appended claims and the reasonably equivalent structures tothose defined therein.

We claim:

1. In a drawer suspension support comprising: a case rail, a suspensionrail, and a drawer rail; said case rail and said drawer rail each beingtelescopically received by portions of said suspension rail;anti-friction means separating said drawer rail from said suspensionrail including at least one ball, and separating said suspension railfrom said case rail including at least one ball; a pair of cooperativeresilient stop elements mounted respectively to the walls of said drawerrail and suspension rail on opposite sides of one of said balls, and asecond pair of cooperative resilient stop elements mounted respect-ivelyto the walls of said suspension rail and case rail on opposite sides ofthe second one of said balls; said stop elements being placed instraddling abutment with said balls upon extension of said support; andeach of said stop elements having a wedge-shaped nose to cooperate wit-hthe adjacent wedge shaped nose of the cooperative stop element and wedgea ball therebetween, thereby pressing the resilient stop elementstightly against the walls of said rails; said rails including metallicsafety stops severed and deformed to cooperate and form a pair ofcooperative safety stops between said case rail and suspension rail, andra second pair of cooperative safety stops between said suspension railand drawer rail; said safety stops being spaced to normally be free ofoperative engagement except upon slight over-extension of said supportwith failure of said resilient stops.

2. The support in claim 1 wherein each resilient stop elements includesa bumper with a slot engaged with a generally C-shaped portion of ametallic clip, the other end of said clip having a tail slidably securedunder a tab severed Iand deformed from the wall of the respective railto form a receiving slot.

3. In a drawer suspension support comprising: a case rail, a suspensionrail, and a drawer rail; said case rail and said dr-awer rail each beingtelescopically received by portions of said suspension rail;anti-friction means separating said drawer rail from said suspensionrail including at least one ball, and said suspension rail from saidcase rail including at least one ball; a pair of resilient stop elementsmounted respectively to the walls of said drawer rail and suspensionrail on opposite sides of one of said balls, and a second pair ofresilient stop elements mounted respectively to the walls of saidsuspension rail and case rail on opposite sides of the second one ofsaid balls; said stop elements being placed in straddling abutment withsaid balls with extension of said support; each of said stop elementshaving a resilient bumper with a ball-contacting surface tapered towardthe wall upon which the stop element is mounted, to cause a portion ofthe abutment force to press the bumper tightly against the wall forstability; said bumpers each having a slot in its outer portion, spacedfrom said tapered surface; a generally U-shaped, metallic holding clipelements engaged in said slots of said bumpers, and having a tongueextending therefrom away from said bumper; a t-ab severed and deformedfrom the respective rail wall and slidably receiving said tongue toanchor the bumpers against movement with impact.

4. In a drawer suspension support comprising: a ease rail, a suspensionrail, and a drawer rail; said case rail and said drawer rail beingtelescopieally received by said suspension rail; a first pair ofcooperative resilient stop assemblies mounted to said case rail andsuspension rail and having cooperative elastomeric bumpers providingcushioned stop action; a second pair of cooperative resilient stopassemblies mounted to said suspension rail and drawer rail and havingcooperative elastomeric bumpers providing cushioned stop action; a pairof safety stops between said drawer rail and suspension rail and asecond pair of safety stops between said suspension rail and case rail;said safety stops normally being out of operative engagement withextension of said support, except with slight over-extension thereofupon failure of said resilient stops.

References Cited by the Examiner UNITED STATES PATENTS 1,068,375 7/13Watson et al 312-339 1,135,235 4/15 Weiss 312-339 1,227,939 5/ 17Sampson et al 312-339 X 2,012,530 8/35 Eustis S12-335 2,056,407 10/ 36Metcalf 312-335 2,559,380 7/51 Wikman e 312-348 X 3,009,755 11/61 Rackow312-339 FOREIGN PATENTS 122,359 9/ 46 Australia.

FRANK B. SHERRY, Primary Examiner.

CHANCELLOR E. HARRIS, Examiner.

1. IN A DRAWER SUSPENSION SUPPORT COMPRISING: A CASE RAIL, A SUSPENSIONRAIL, AND A DRAWER RAIL; SAID CASE RAIL AND SAID DRAWER RAIL EACH BEINGTELESCOPICALLY RECEIVED BY PORTIONS OF SAID SUSPENSION RAIL;ANTI-FRICTION MEANS SEPARATING SAID DRAWER RAIL FROM SAID SUSPENSIONRAIL INCLUDING AT LEAST ONE BALL. AND SEPARATING SAID SUSPENSION RAILFROM SAID CASE RAIL INCLUDING AT LEAST ONE BALL; A PAIR OF COOPERATIVERESILIENT STOP ELEMENTS MOUNTED RESPECTIVELY